I. Field of the Invention
The present invention relates to machine tools, and more particularly to a quick-connect and disconnect means for attaching a working member such as a workpiece, a tool or the like to a machining device such as a lathe, a mill, a grinder, or a multiple-tool turret or head, or for gauging purposes or the like.
II. Description of the Prior Art
Quick-change tool adapters or mounts of various types are well known. For example, it has been known to employ paired tool holders affixed one each to a working member and to a machining device. The holders are then joined by a stem on one of them which is drawn by a draw means on the other, to bring the holders into abutment. The draw means can comprise balls or rollers forced by an axially movable, spring-loaded sleeve into a V-notch or another ramp surface on the stem. At least one past adapter has included a particular mating configuration on the abutting faces of the holders in order to center them by perpendicular movement when they are drawn into engagement with one another.
While these prior adapters have been generally adequate for their intended purpose, there use has entailed some drawbacks. The prior adapters have generally included a draw means which was fixedly mounted to (and thereby maintained in a fixed position relative to) the machining device, so that any axial misalignment of the drawing means and the mating faces meant that the tool holder was either loose, or mounted at an angle, even though the stem was firmly drawn. In either case, the precision of alignment of the working member and the machining device was adversely affected.
Typically, such tool adapters at best possess a precision of about one one-thousandth of an inch. This precision is insufficient for much machining work which needs to be performed today. Also, prior changers have involved complex draw and alignment structures, costly to construct and difficult to maintain and keep clean. This last problem is particularly acute in machine shop environments, where the introduction of oil, abrasive or machined metal powder or particles between the mating faces of the holders is common.